Stuck in the Pharos. Please help.

[Optium]

I just beat Fenrir and I had to touch the same altar as I did on the floor
below, but I didn't realize that's what I had to do, so I touched another
one. Nothing seemed to be happening and I looked for the solution online.
I touched the corresponding altar but the elevator never appeared. I'm not
sure what to do. :\

.opt

[Renmiri]

Black, red, green, the sacrifice altar, then you need to look for a fake wall, demolish it and touch the white stones inside.

Oh, and you have to touch the elevator gate too iirc.